AI-assisted JS to TS conversion
Converts pasted JavaScript into TypeScript with type annotations, interfaces, generics, and inferred types.
JS2TS
ClaimJS2TS is a free web-based converter that uses AI to turn JavaScript into TypeScript, plus related JS, TS, Zod, and JSON conversion tools.
JavaScript to TypeScript conversion
JS2TS is an online converter for JavaScript-to-TypeScript migration. It uses AI to turn pasted JavaScript into typed TypeScript by adding annotations, interfaces, generics, and other type constructs that fit the input code.
The site positions the tool as a quick way to reduce manual migration work: instead of renaming files and adding types by hand, users paste code, convert it, and copy the TypeScript output. The same site also offers adjacent tools for TypeScript to JavaScript, TypeScript to Zod, and JSON to TypeScript conversions.
Core features
Broad TypeScript syntax coverage
Supports common migration patterns including function parameters and return values, object shapes, arrays, unions, intersections, classes, async code, and module syntax.
Fast browser-based workflow
Provides a simple paste-and-convert workflow with instant output in the browser.
Reverse conversion tool
Offers a separate TypeScript to JavaScript converter for stripping TypeScript-specific syntax back to plain JavaScript.
Related conversion tools
Includes adjacent converters such as TypeScript to Zod and JSON to TypeScript for related developer workflows.
No-login, real-time processing
States that conversions are processed in real time and not stored on the server.
Typical use cases
Migrate JS projects to TypeScript
Convert existing JavaScript files into typed TypeScript when you want faster migration than doing the annotations by hand.
Work with React and Node.js code
Transform React components and Node.js modules into typed output that better fits larger application codebases.
Convert TypeScript to JavaScript
Strip TypeScript syntax back to plain JavaScript when you need code that can run without a TypeScript compiler.
Derive validation schemas from types
Generate Zod schemas from TypeScript interfaces when you need runtime validation in addition to compile-time types.
Create TypeScript interfaces from JSON
Turn JSON into TypeScript interfaces when starting from API responses or structured data payloads.
Pros and Cons
Pros
- Free to use with no account, login, or credit card required.
- Produces typed TypeScript from pasted JavaScript in a simple browser workflow.
- Covers a wide range of common migration patterns, including React and Node.js code.
- Processes conversions in real time and says it does not store or log submitted code.
- Offers related tools for adjacent conversion tasks on the same site.
Cons
- The site notes that very large codebases may work better when pasted in sections incrementally.
- For complex or ambiguous code, the converter may fall back to `any` or `unknown`, which may still need manual refinement.
FAQ
How do I convert JavaScript to TypeScript?
Paste JavaScript into the converter, click Convert, and copy the TypeScript output. The tool automatically adds type annotations, interfaces, and generics.
Is the JavaScript to TypeScript converter free?
Yes. The site states that the JavaScript to TypeScript converter is completely free and does not require an account, login, or credit card.
What kinds of TypeScript patterns does JS2TS support?
The converter handles common patterns such as function parameter and return types, object interfaces, arrays, unions, intersections, generics, class property types, async return types, module imports and exports, React props, and type inference from usage.
Does JS2TS store my code?
The site says conversions are processed in real time and your code is never stored or logged on its servers.
Does JS2TS work with React and Node.js code?
Yes. The site says it works with React components, Node.js modules, ES6+ syntax, CommonJS, and ESModules.
Quick Facts
- Category
- Developer Tool
- Platform
- Web app
- Primary use
- JavaScript to TypeScript conversion
- Source domain
- js2ts.com
- Pricing
- Free online tool
- Related tools
- TypeScript to JavaScript, TypeScript to Zod, JSON to TypeScript